Although I'm technically being a thread-mancer, resurrecting this thread from the dead, it's still on the first page so I thought it'd be alright.

Once you have your now dead, hopefully, iguana, you want to slit it open on the underside, along its stomach. Clean it accordingly, taking out all the internal organs and so on. Once that's completed, skin it to the best of your ability. And once that's done, put it in ice cold water so you can keep it for a few hours up until you're ready to prepare it for eating.
If it's a large iguana, you can slice it up very much like you would a chicken. If not, you can prepare it whole.
From my understanding, the best way to prepare an iguana is to boil it, adding whichever seasonings you so desire. Not wanting to ever try this myself, I bring forth knowledge from wikiHow. lol.